On the SitePoint PHP blog Younes Rafie asks the question "Can we have static types in PHP without PHP 7 or HHVM?" One of the main features introduced by both of these versions (or platforms) is the ability to type things strictly and enforce more correct data handling. Previously PHP has been a "lazy typing" language and would regularly shift the type of a variable depending on the immediate need. Obviously, this can lead to unpredictable behavior.

Now that PHP 7 has been out for a while with interesting features like error handling, null coalescing operator, scalar type declarations, etc., we often hear the people still stuck with PHP 5 saying it has a weak typing system, and that things quickly become unpredictable.

Even though this is partially true, PHP allows you to keep control of your application when you know what you’re doing.

They show how, through a series of examples, to add a bit of additional validation with exceptions to ensure the input is the correct type. However this can be a bit more time consuming and difficult to remember so the team at Box put together the augmented types extension that brings some of the static typing to PHP 5.x. They help you get it installed and working in your PHP installation and include an example of it in use with DocBlock-based type hints. The extension provides handling for the basic types as well as arrays, multiple arguments, default values and return types.